The present invention relates generally to a solenoid valve, and more particularly to a normally open solenoid valve that is open during non-energization.
A typical normally open solenoid valve is described, for example, in TECHNICAL PAPER SERIES 930505 entitled xe2x80x9cABS5 and ASR5: The New ABS/ASR Family to Optimize Directional Stability and Tractionxe2x80x9d, pp. 11-18, published by Society of Automotive Engineers (SAE). This solenoid valve comprises a roughly cylindrical valve body, a cylinder having an end closed by an end of the valve body fixed thereto by welding, a valve-seat member arranged in the valve body, a plunger slidably arranged in the valve body to have a front end with a valve part seated on the valve-seat member, a moving part slidably arranged in the cylinder to abut on a base end of the plunger, a spring interposed between the valve-seat member and the plunger to bias the plunger and the moving part in the valve-opening direction, and a coil wound on the outer periphery of the valve body and the cylinder. When energizing the coil, a magnetic path is formed from the solenoid yoke to the valve body through the moving part so as to produce an electromagnetic force, which moves the moving part against a biasing force of the spring, closing the valve.
In the above solenoid valve wherein energization of the coil creates magnetic path as described above, the plunger, located in the magnetic path, is made of a non-magnetic material such as stainless steel so as not to provide a magnetic force per se, securing the valve opening/closing responsibility, etc. Moreover, although the valve part of the plunger needs to have higher hardness due to repeated collision with the valve-seat member, the valve part of the plunger of non-magnetic material such as stainless steel is of lower hardness, requiring a particular treatment for increasing the hardness for the purpose of preventing wear.
As described, in the typical solenoid valve, the plunger is high in material cost due to use of a high-priced non-magnetic material, and has increased number of working processes due to need of a particular treatment for increasing the hardness, leading to the disadvantage in manufacturing cost.
It is, therefore, an object of the present invention to provide a solenoid valve that is free of the above disadvantage, and allows a reduction in manufacturing cost.
The present invention provides generally a valve arrangement, comprising:
a body with an end face;
a moving part slidably received in the body, the moving part being provided with an end face;
a plunger slidably received in the body, the plunger having one end fading an end face of the moving part, the plunger being formed out of a magnetic material; and
a protrusion formed at the one end of the plunger, the protrusion abutting on the end face of the moving part.
One aspect of the present invention is to provide a solenoid valve, comprising:
a body with an end face;
a seat member slidably received in the body;
a moving part slidably received in the body, the moving part being provided with an end face;
a plunger slidably received in the body between the seat member and the moving part, the plunger having one end facing the end face of the moving part, the plunger being formed out of a magnetic material;
a protrusion formed at the one end of the plunger, the protrusion abutting on the end face of the moving part; and
a valve part arranged at another end of the plunger, the valve part abutting on the seat member.
Another aspect of the present invention is to provide a valve arrangement, comprising:
a body with an end face;
a moving part slidably received in the body, the moving part being provided with an end face;
a plunger slidably received in the body, the plunger having one end facing an end face of the moving part, the plunger being formed out of a magnetic material; and
a protrusion formed at the one end of the plunger, the protrusion abutting on the end face of the moving part,
wherein a predetermined clearance is defined between the end face of the body and the end face of the moving part,
wherein during energization, a predetermined magnetic path is formed from the body to the moving part, the predetermined magnetic path producing an attraction force between the body and the moving part across the predetermined clearance, the attraction force pressing the moving part toward the plunger to provide a closed valve state,
wherein a predetermined magnetic flux running along the magnetic path becomes saturated at the protrusion,
wherein the protrusion has a predetermined sectional area allowing saturation of the magnetic flux, and
wherein the protrusion has a protrudent amount greater than the predetermined clearance.
A further aspect of the present invention is to provide a valve arrangement, comprising:
a body with an end face;
a moving part slidably received in the body, the moving part being provided with an end face;
a plunger slidably received in the body, the plunger having one end facing an end face of the moving part, the plunger being formed out of a magnetic material; and
a protrusion formed at the one end of the plunger, the protrusion abutting on the end face of the moving part,
wherein a predetermined clearance is defined between the end face of the body and the end face of the moving part,
wherein during energization, a predetermined magnetic path is formed from the body to the moving part, the predetermined magnetic path producing an attraction force between the body and the moving part across the predetermined clearance, the attraction force pressing the moving part toward the plunger to provide a closed valve state,
wherein a predetermined magnetic flux running along the magnetic path becomes saturated at the protrusion,
wherein the protrusion has a predetermined sectional area allowing saturation of the magnetic flux,
wherein the protrusion has a protrudent amount greater than the predetermined clearance,
wherein the protrusion is arranged at a center portion of the plunger at the one end thereof, and
wherein the protrusion is circular in cross section.